This work proposes to study pressure and flow events at the interface between the left ventricle and the systemic arteries as an interactive event which depends on properties of both components of the left ventricle/artery system. To do this, a novel animal experiment will be performed in which pressure, flow, and volume variables are measured while a well-controlled and sudden flow pulse is delivered to this interactive system. The system response to this sudden pulse, as well as the natural pressure and flow behavior, will be used in separate analytical procedures to identify the properties of both system components individually and the system as a whole. The identification procedures will be conducted using data acquired from a variety of system states. Identification will be directed at providing values for elements in five different models of the ventricle/artery system. These models will be compared with one another in terms of their ability to predict the observed hemodynamic events. Through this comparison of model predicted and actual observed events, the adequacy of various concepts for describing the operation of this system will be evaluated. From this, a conceptual tool will emerge which will find application in the study of physiology in the intact animal and in the assessment of disease processes in man.